Spark plttq



July 17, 192s.`

I. W. FARQUHARSCN snuit PLUG Filed Jan. 24, 1925 PatentedA July 17, 1928. 1

UNITED STATES PATENT oFFiCE.

IBVING w. rARQUHARsoN, 'or MEDIA, PENNSYLVANIA.

SPARK PLUG. l

Application med January 24, 1925. seriai No. 4,413.

rlhis invention relates to a spark-plug as tion I have shown in the accompanying u sed in the cylinders of internal combustion drawings one form thereof which is at pres! engines. ent preferred by me, since the same has been The use of spark-plugs in an engine of found in practice `to give satisfactory and 5 the above mentioned type is attended by an reliable results, although it is to be under- 6o accumulation of lubricant, soot or carbon, stood that the various instrumentalities of and other foreign matter, to such an extent which my invention consists can be varias to result in short cireuiting the current ously arranged and organized and that my or to the production of a bridge across the invention is not limited to the precise ararc gap between the terminals, thus precludrangement and organization of the instru- 65 ing the formation of a spark, interfering ment-alities as herein shown and described.

with the operation of the engine, and re- Referring to the drawing in detail, the quiringthe operator to remove, clean and .reference numeral 1,\designatesametal bushreplace the plug. king which is relatively short 1n length as i5 `One object of this invention is to overcome compared with those now in use and is eX- 70 the foregoing, and other, objections, and to ternally screw-threaded at one end as at 2, produce a simple, eliicient,` and economical for a portion of its extent, in order that it construction wherein the accumulation of may be screwed into the cylinder of an inforeig'n matter is minimized so as to obviate ternal combustion engine, the opposite end the production of a short circuit. being squared as at 3 for tool accommoda- 75 Another object resides in the provision of tion. The bushing at its inner end is progeneral details of construction and aiirangevided with an annular plane surface 4, in ment and combination of parts for attaining ccntradstinction t0 the ugual annular rethe results sought by the foregoing object. cessed portion. commonly employed. EX-

Another object is to provide a structure tended throughthe bushing is a core 5 of 80 in which oil accumulating pockets are avoidporcelain, mica, lava or equivalent material ed inthe plug bushing. provided withan electrode (i. The core is A still further object is toprovide a struccylindrical throughout the major portion of ltll'e 1D WlllCll il relatively SllOlll bushing' but itsextent and is provided with a Shoulder 7 :io a relatively 'long core and its con'lplcmcntal ,which abuts against the annular seat 8 with electrode is provided in order that vthe elcc- .the bushing 1, and is clamped to place bv tI'OdG IIll'y pl'OjGCt Weill llllO lie GXPlOSlOll VIngang gland 9, Thai", @11d 0f the, (50i-g chamber of an .internal Vcombustion engine which is for penetration of a cylinder or to obtain sparking as near the center of the Vignition Chamber relatively 10mg LS Coma5 compressed charge as possible. `By con pared to cores now in use and gradually ta- 90 structing a spark-plug to attain the above pers cone-fashion so that its cross-sectional objects I am enabled to effect a Saving 111 area gradually reduces as it nears the sparkbOtll metal EIIlplOyQd in lill@ bushing und 111 ing point, 10 0f the, electrode, The @0I-9, at time' COHSUmd in making the lOUSlliHg. that portion thereof, immediately adjacent 40 Other and further objects not at `this time the annular surface 4 of the bushing or the 95 more particularly referred to i will appear juncture Vof the cylindrical and tapered parts hereinafter. is provided with an annular raised portion,

The invention consists of the novel conas at 11 to prevent an oil collecting pocket struction hereinafter described and finally at this place. Carried b the inner end of claimed. the bushing is a secon electrode 12 ar- 100 The nature, characteristic features and ranged .in parallelism with electrode 6, its scope of the invention will be more fully terminal being bent laterally toward the understood from the following description sparking point 10 to form a sparking foot taken in connection with the drawings form- 13. The object of this construction is to ingpart hereof, and in which: avoid any semblance of a shell or housing 105 Fig. 1, is a view in elevation of the spark around the core as in common use and which plug; and y collect oil vapors from the oil feed of the Fig. 2, is a central longitudinal sectional engine and as the flash of the ex losion can view of Fig. 1. not reach into this shell or housing, the oil For the purpose of illustrating my inven deposits are baked to a carbon which causes il a short circuit of the ignition current and it `fails to do `lits work. By experiment I have proven, when a spark-plug islconstrueted, as shown, without housing or shell covering core, thatthe oildoes not collect around the core in sufficient quantities to resist the eX- plosion `fiashes, but is burned off at each iiiiring oil" the gases. The relative distance be tween the core and electrode dfmust be very carefully placed to avoid possible oil pockets. A further beiieilt is derived by having the coi'e project well into the explosion chamber to get tliespaifl; as near the 'center *ofthe compressed charges as possible, with the Aattending results that the flash passes 'from the center tothe outside, whereas in the other methods, the fiash is started on fthe extreme outside and has 'to ypass clear across the entire charge, with the result of considerable waste o gas -at each explosion. Thus Aobviafte the use of the Dule double Y ignition 'with the necessary Vuse of two Vsparkeplng's. It Ais however obvious"that Ithe Illini length oi the lcore and electrode d2 Iniust be controlled vaccording to the construction of `the particular lengine in which used, but under no 'condition are these tivo lparts to be covered Aby shell, housing or covering, of

any description, either in part or whole,

singl" or together, as the avoiding of oil poclretsris the main and fundamental principle 'of this invention. l wish `iii'ii'ther to'set ylorth thatvin constructing a spark-plug as shown, there is aV saving or' about rl/Sgot the metal and of the labor used in the standard plugs on the market.

fIt 4will now be apparent that I have devised-a novel and vusefulconstruction 4which embodies the'featu'res of advantage enumerated as desirablek in fthe Astatement of the `invention andthe `above `description 'and while I have in the present instance shown and described the lpreferred embodiment t'hereol which has been :found in practice to give satisfactory and reliable lresults, it is to be understood that .the same is susceptible of vmodification vin vvarious particulars without departing from the spirit or scope of the invention or sacrificing any of its advani-tages. e y l Having thus described my invention what I claim as new and desire to secure by Let-- ters Patent, is; f

1. AIn a sparkling, a bushing the inner fend :of which has anV unflanged,` plane annular surface, an insulator core having an electrode therein cariiiedby said bushing, a portion of said core being cylindrical and the major portion ytapering -at its inner end, and being e;-.posed throughout saidinajor portionZ the juncture oi'V said cylindrical andftapored 4parts forming a raised Van'nular part 11 which isypositioned immediately acont said bushing and said tapered Ypart of lthe insulator core being at least twice the length oi said bushing, `and an additionaleleetrode carried by 'thebushrng the Ina-)or portion "off which parallels the ltapered rpart of vthe core` electrode and is of substantially the same length as said tapered part, the terminal of which is bent laterally at right angles tofA ward the sparking point foi lthe leo'refelectrede, but which does not extend therebeyend. f

2. Vln a spark plug, a vbuslfiin-g vhaving `an un'langed inner end and lan insulator `core carried therein, an electrode passing through and movabiy positioned within the core, aV

portion of said core being cylindrical and i the major portion tapering atits inner end and protruding. 'beyond 'the bushing, said maj or portion being exposed throughout land forming with said cylindrlieal portionY raised annular part positioned Eilfnniediately adjacent said end of lthe bushing, an additional electrode carried by "the bushing, the maj or portion of which parallels the tapered part of the core electrode and is of lsiib'stai'i? tially the saine length as the tapered part of said core electrodesaid additionalelectrode :being bent laterally at right anglesto `the sparking point of the core electrode. y n ln testimony whereof, I have 4hereunto signed my name. Y

ravine W. rhiiounansofju.: y 

